Howard Dean was "An early front-runner in the 2004 Democratic Presidential nomination," the second longest serving governor of Vermont, and is the Democrat Party's national Chairman, a post he held from 2005 to 2009. Wikipedia - Howard Dean

"Once I determined that it was best for the cause that I step down, the question became 'should I endorse another candidate?' I made the decision to do so. There is a candidate that meets several criteria that are critical from my point of view...
And finally, and very importantly, he can go the distance...

"And so today, I am doing two things that I believe are in the best interest of this cause.
And that cause is of course a secure America.
I am withdrawing from the race and I am endorsing Governor Mitt Romney for President of the United States.

"Throughout the campaign I have learned a great deal about the candidates.
I have certainly been impressed with Governor Romney's ability to solve very complex problems
and I believe he is a man of personal integrity and great character.
I think he would bring honor to the Oval Office.
So I am happy to do this thing". Tom Tancredo (4:15 minutes into statement)

(Including quotes from the two most recent republican presidents and from Senator McCain.)

MITT ROMNEY HAD THE MOST SUPPORT AMONG PUBLIC FIGURES:

By Feb 23, 2007 (approximately one year before Super Tuesday) he had 245 total endorsements, followed by 118 for McCain and 22 for Giuliani. That was more than twice the endorsements of the next leading candidate and ten times the endorsements of the candidate trailing after that.
The names of each endorser are given for each candidate.

On Aug 15, 2007, a website that tracked only endorsements by key political figures showed him still receiving the widest support, having a total of 68 key endorsements, with 40 for McCain and 4 for Huckabee.
That website divided the endorsements into four tiers, with tier 1 being current U.S. Senators, U.S. Representatives and Governors, tier 2 being former U.S. Senators, U.S. Representatives and Governors, tier 3 being RNC Committee members and
tier 4 being the number of states in which the candidate had won the endorsement of a majority of state legislatures. In each category Mitt Romney had the lead.

By January 1st 2008, another website that tracked only first tier endorsements showed Romney still had the greatest support, with 41 total tier one endorsements, while McCain had 32 and Huckabee had 5.*

*Counts, such as those given in the above references, may not be exact. For example, subtotals included Senator Lott who resigned from Senator McCain's campaign, but not Senator Craig who resigned from Governor Romney's and a subsequent list missed Rep. Mulvaney's (R-SC) Romney endorsement.

Also of note, these are endorsements of public figures, including elected officials. Many private citizens whose name and face are not known to the public came out in favor of or endorsed one candidate or another, but in the end their voice matters most in the election booth.
Sen. McCain won the election, and emphasized support he had among individuals in different groups, such as the military. In January 2008, when a talk show host had on his show a former secretary of defense (a visible public figure) who endorsed McCain, the host joked that at least someone endorsed Senator McCain.
However, as the guest noted, many people in the pentagon and former government employees who worked under that secretary of defense endorsed Sen. McCain. The host noted that since McCain heads a committee over the military, many of those may be people who did not want to jeopardize funding or programs they were leading. However, if lists of private citizens were counted, such as those people, and including those involved in the political process, just as Sen. McCain won the election, he very well may have led in endorsements.

Governor Romney received enthusiastic endorsements as can be seen by reading a sampling of quotes below.
Some have tried to downplay Governor Romney's support by noting only a few incumbent governors endorsed him. However, when the presidential primary voting began with the Iowa Caucus in January 2008, Mitt Romney had received four endorsements from incumbent governors to McCain's three, although a governor who endorsed Romney early on was leaving office and soon became a former governor. But as Super Tuesday neared, a few more governors endorsed Senator McCain.

(Some have felt the governors endorsing McCain around this time had more liberal views on immigration and other issues that best matched Senator McCain. Thomas Sowell had this perspective: "John McCain has now been restored to the position of front runner that the media gave him at the outset.

"Other Republicans are jumping on his bandwagon. This may have less to do with McCain’s own qualities than with the prospect of getting Cabinet posts or Supreme Court appointments as rewards for their political support.")

As Governor Romney led in overall endorsements and in endorsements in so many categories throughout the campaign, often by significant margins, his falling a few governors' endorsements behind McCain in his final two weeks was one area McCain supporters emphasized. Even at that, Governor Romney received a total of nine endorsements from serving and retired governors, a very respectable show of support for a presidential primary, but especially for an underdog in the election.

More significant, is that Governor Romney led in congressional endorsements, the governing body the next president would work with. Also significant, Governor Romney received a competitive (although smaller) number of endorsements in the branch of congress which McCain spent over 20 years in— a branch with less than 50 republicans, most on at least their second 6-year term, who knew McCain well.

Also significant is that the most politically active and informed republicans favored Governor Romney by a noticeable margin.
This was reflected in part by Mitt Romney receiving the most endorsements in all tiers. But it was also reflected in his receiving overwhelming support from conservative talk show hosts, strong, widespread support by conservative leaders and pundits, and by his winning 8 out of 10 state caucuses, which the more politically active and informed members of the republican party generally participate in.
If the average republican primary voter had been as involved in the election and accurately educated about the candidates, Mitt Romney may have won the most state primaries as well.

"I think he's (Romney's) one of the brightest people I've ever seen in public office," Owens said on the show. "He's a businessman, he's a manager. He is a conservative, he wants to cut taxes."

In a statement, Romney said he was pleased to have a senior advisor who was elected to the Colorado governorship with the greatest majority in the state's history.

"In his eight years as Governor of Colorado, he has shown a commitment to finding the kinds of new and innovative solutions that America needs if we are to meet a new generation of challenges," Romney said.

MY FONDEST MEMORY of my two terms as governor of Massachusetts in the 1990s was that we reversed the tax-and-spend policies of the Dukakis years, and put the Commonwealth on a new diet of "Live Free or Die" philosophy and "supply-side" economics. From 1991 to 1997, we had 19 tax cuts in Massachusetts, and not a single tax increase. The result, predictably, was an economic resurgence.

I was therefore thrilled when Mitt Romney was elected governor in 2002 and accelerated the Commonwealth's course of fiscal conservatism.

I believe that Romney was a very effective leader for our state. He came into office facing a nearly $3 billion budget gap. Even Democrats conceded that this was the worst fiscal crisis since the Depression. Instead of raising taxes or borrowing more money, Romney cut spending and closed the budget gap. As one commentator said, he "didn't just go after the sacred cows, he went after the whole herd." In his first year, government spending declined from $22.8 billion in Fiscal 2002 to $22.4 billion in Fiscal 2003. This was a tremendous success that Romney would continue to match throughout his four years as head of the Commonwealth. Seeing what he did in Massachusetts, I am proud to support Romney and believe he is the kind of leader we need in Washington.

Anyone who claims that Romney did not cut taxes in Massachusetts is simply mistaken. He cut capital gains taxes, benefiting well over 150,000 residents. Thousands more are currently benefiting from new jobs in the biotech field because of Romney's manufacturing tax relief and because he made the investment tax credit permanent. Thousands of Massachusetts families saved their hard-earned dollars when Romney enacted sales tax holidays. Seniors are benefiting from property tax relief proposed and signed into law by Romney. Our honorable veterans and National Guard members have several new tax breaks because of Romney's belief that they should be taxed less. Commuters can now deduct expenses for travel because Romney believes they shouldn't be penalized for helping increase commerce.

Romney's fiscal achievements were not his only accomplishments in Massachusetts.

Besides tackling government waste and inefficiency, he halted the state's economic tailspin and added tens of thousands of new jobs. He signed into law a health insurance reform modeled on a conservative market-oriented approach that emphasizes personal responsibility. He started the Adams Scholarship, a merit-based program that awards the top 25 percent of high school students in Massachusetts with four years of free tuition at a Massachusetts public college or university. He instituted English immersion in the public schools and abolished the old bilingual education system.

This is a real record of achievement that Romney is running on across the country. I am proud to endorse his candidacy for president of the United States.

"At this moment our nation faces unprecedented challenges, and Governor Romney has the experience, vision and values needed to strengthen our country for future generations," Cochran said in a statement issued by the Romney campaign. "Governor Romney is a man of outstanding judgment and strong character."

Senator Cochran of Mississippi became the sixth U.S. Senator to officially endorse Governor Romney by that date.

Congressman Bilbray said, "Our country faces unprecedented challenges and we need a leader with proven executive leadership. That leader is Mitt Romney. He can strengthen our economy because he has worked firsthand in the economy. He will work to strengthen our immigration laws without allowing amnesty to 12-20 million illegal immigrants. I am proud to support Governor Mitt Romney and his campaign to be our next President."

Congressman Bilbray is Chairman of the Immigration Reform Caucus and a San Diego native.

"He's established himself as the conservative candidate who stands for a strong economy," Burkhalter said. "He's a turnaround artist. Everything he's ever taken on, from Massachusetts to the Salt Lake Olympics, he's turned around. We need that in Washington."

Speaker Jetton said, "Governor Romney is a strong conservative leader who will restore fiscal discipline in our nation's capital. As Governor, he fought for traditional marriage and against tax increases that would have made it harder for businesses to grow. He has the values and the vision that are needed to keep America strong."